1. Field of the Invention
The invention relates to devices that stabilize the lens capsule during or after cataract removal.
2. Discussion of Related Art
The clouding of the human eye is referred to as "cataract." Capsulorhexis involves tearing a generally circular opening (capsulotomy) through the anterior capsule of the capsular bag of the human lens. This opening or capsulotomy is bounded circumferentially by a continuous annular remnant edge of the anterior capsule, i.e., the edge is smooth and not jagged. During a cataract operation, the cataractous nucleus and cortex of the natural lens is removed from the capsular bag and an artificial lens implant is inserted into the bag through the capsulotomy.
Endocapsular tension rings are conventionally used to stabilize the lens capsule during cataract removal or after cataract removal. These rings consist of near circular plastic rings, which are inserted into the capsular sac that surrounds the human lens. These devices are currently used in the United States on an investigational basis and also abroad.
Iris retractors are used to enlarge the iris by retracting the same outwardly, thereby expanding the pupil, for the purpose of providing exposure of a cataract during cataract removal procedures. These retractors may be rigid or flexible, and each has an end configured into a hook. In particular, each has the characteristic of a relatively short shank length of approximately 1.0-1.25 mm, although there is a patent disclosure of a shank length between 1.0-1.5 mm. The shank length is the distance between the trough of the bend of the hook to the termination end of the hook's shank.
The inventor has used such iris retractors, which are used to retract the iris on a temporary basis, in an attempt to retract the lens capsule and has used them also to provide fixation to the lens capsule and enclosed cataract in numerous patients. However, the inventor found that such iris retractors provide non-constant fixation and frequently slip off the capsule so to render than unreliable for such use in retracting the lens capsule. Furthermore, such retractors do not restrain the peripheral regions of the capsule (the equatorial capsule). These regions are thus free to be attracted to various aspirating instruments used for cataract removal. The capsule may thus be easily damaged by such instruments.